Teaching is learning, not simply in the sense that the teacher always learns the most about the subject—which, of course, is certainly true—but in the sense that we teachers are all the time learning from experience what to do and what not to do. There are no formulas or recipes for this. One key, however, is to realize from the outset that what works one day may not work another.
Why? Because the teacher’s classroom success (or lack thereof) is dependent not only on his own preparation and knowledge but on the preparation and receptivity of his students, whose emotions, hormones, and amount of sleep the night before will inevitably take a toll on how a given class period goes. You can’t control this, but you can learn to be flexible and to respond to the sea changes of the classroom. This learning takes time, however, so be patient with yourself.
I would add only this: A good teacher needs to be humble while at the same time exuding confidence. A paradox for sure, and doubtless one application (among many) of the Dominical principle that you mustn’t “let your right hand know what your left hand is doing”. Students respond poorly to the pompous know-it-all who treats them with disdain, but at the same time they need to know who’s in charge … you! Showing that you really love what you’re doing helps in striking the right balance.